Transcostal high-intensity-focused ultrasound:: ex vivo adaptive focusing feasibility study
Transcostal high-intensity-focused ultrasound:: ex vivo adaptive focusing feasibility study
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DOI：
10.1088/0031-9155/53/11/012
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发表时间：
2008-06-07
影响因子：
3.5
通讯作者：
Fink, M.
中科院分区：
文献类型：
--
作者：
Aubry, J-F;Pernot, M.;Fink, M.
离体实验已经通过离体猪肋骨与骨、软骨、肌肉和皮肤进行。对胸腔的畸变效应进行了实验研究。在低功率下研究了肋状结构的自适应超声聚焦。在没有任何校正的情况下，焦平面中的压力场都受到不均匀衰减和相位失真的影响，并且观察到三个主要效应：主瓣的平均2 mm的移位、主瓣的半宽度的平均1.25 mm的扩展和副瓣水平的高达20 dB的增加。由于时间反转聚焦，获得了5dB的次瓣降低，并且沉积在目标位置处的能量与治疗阵列发射的能量总量之间的比率比未校正的高6倍。时间反转通过在肋骨之间自动超声来最小化肋骨的加热，如通过使用放置在胸腔上的不同位置处的热电偶的温度测量所证明的。它还讨论了如何这种像差校正过程可以实现非侵入性的临床应用。
Ex vivo experiments have been conducted through excised pork rib with bone, cartilage, muscle and skin. The aberrating effect of the ribcage has been experimentally evaluated. Adaptive ultrasonic focusing through ribs has been studied at low power. Without any correction, the pressure fields in the focal plane were both affected by inhomogeneous attenuation and phase distortion and three main effects were observed: a mean 2 mm shift of the main lobe, a mean 1.25 mm spreading of the half width of the main lobe and up to 20 dB increase of the secondary lobe level. Thanks to time-reversal focusing, a 5 dB decrease in the secondary lobes was obtained and the ratio between the energy deposited at the target location and the total amount of energy emitted by the therapeutic array was six times higher than that without correction. Time-reversal minimizes the heating of the ribs by automatically sonicating between the ribs, as demonstrated by temperature measurements using thermocouples placed at different locations on the ribcage. It is also discussed how this aberration correction process could be achieved non-invasively for clinical application.